This invention relates to the improvement of combustion in fuel-burning devices, more particularly to the improvement of efficiency of liquid fossil fuel burning systems such as oil burners, e.g. those used in home and/or industrial heating units.
It is known that combustion devices which burn hydrocarbon fuels generally are more efficient and economical when supplied with moisture-laden air or droplets of water suspended in air to the manifold to be mixed with the vaporized fuel. See, e.g., U.S. Pat. No. 1,618,602, Meyers, U.S. Pat. No. 1,775,263, Wiegland, and U.S. Pat. No. 3,814,567, Zink. The reason for the increase in combustion efficiency is unclear. It has been postulated that the water vapor acts catalytically to aid in combustion, since water is a reaction product from the combustion of hydrocarbon fuels, and the presence of reaction product in a reaction medium would generally be expected to drive the reaction in the opposite direction or at least slow it down. See U.S. Pat. No. 3,862,819 to Wentworth. Others, such as Zink, supra, have suggested that the water acts as a source of hydrogen which aids in more complete combustion of the carbon. Some have bubbled air through a water layer which is coated with a layer of oil or other hydrocarbon before injecting it into the combustion zone, e.g. Wentworth, supra, and U.S. Pat. No. 1,618,602 to Meyers et al. In such systems, it is possible that the water reacts with other components in the system to produce catalysts or more highly reactive fuels. At any rate, whatever the precise mechanism by which the efficiency is increased, some increase in efficiency has been previously recognized.
Yet in spite of the fact that this phenomenon has long been known, no device which employs the phenomenon to improve the efficiency of oil burners, for example, has been commercially adopted by the industry. The reason for this is believed to be that previously known devices for infusing water vapor or other catalytic vapors into the combustion mixture have not proven to result in the expected increase in efficiency and performance on a dependable basis.
In the Wentworth patent discussed above, there is disclosed a device which utilized the oil burner blower itself to force a portion of the combustion air to bubble through a water layer, preferably covered with a layer of oil. In that device, two taps are made and tubes are inserted into the housing of the oil burner blower, one in order to supply air under pressure to a dip tube extending beneath the surface of a water supply in a container, and another connected to the oil burner blower in such a manner as to obtain a vacuum, and connected to the water container above the water level, so as to apply that vacuum and obtain a pressure differential between the air in the dip tube and the air above the liquid level, thus aiding in the passage of air through the liquid. The Wentworth apparatus imposes a drain on the efficiency of the burner blower, and provides little control over the contact rate between the air and the water. It has been found in practice that the Wentworth system is undependable and erratic in operation, and does not provide adequate increase in performance or savings in fuel cost.
It is accordingly an object of the present invention to provide an apparatus which is effective in decreasing fuel consumption and improving performance of liquid fuel burners.
It is a further object of this invention to provide such a device which provides consistent improvements in performance and fuel consumption over a wide range of operating conditions.
It is a further object to provide such a device in which the operation of the device is easily and precisely controlled and adjusted to maximize its effect, such device being easy to manufacture, install and use.
It is a particular object of this invention to decrease fuel consumption and improve performance of oil burners of the type used in heating equipment.
It is a still further object to provide a method of improving the combustion of hydrocarbon fuels, such as petroleum or fractions or derivations of petroleum.